Add structured multi-project storage

wwwroot/css/app.css

@@ -459,6 +459,19 @@ label {
     height: 18px;
 }
 
+.project-save-option {
+    padding: 10px 11px;
+    border: 1px solid var(--line);
+    border-radius: 6px;
+    background: #fff;
+}
+
+.project-archive-state {
+    color: var(--muted);
+    font-size: 11px;
+    line-height: 1.35;
+}
+
 .map-info {
     position: absolute;
     left: 12px;